I mean, the castle canonically has all kinds of modern tech - I kinda like how a lot of the "mysterious magical shit" going down in Dracula's castle is just... future tech. Because that's probably how a lot of it would come across.

But it's true, that makes it really hard to really pin anything down for historical accuracy! I'd be inclined to say not to worry too much - if anyone is bothered by anachronism, then I figure they probably wouldn't watch the show, so aren't going to be reading fic. Oooor that's just because I'm too lazy to do much research for things like that, haha.

At the same time, it IS fun to get to find out some interesting historical facts. There's stuff like that that isn't always widely known, but is really neat to find out more about.